The shot that saves

A recent large-scale outbreak(eruption,प्रकोप) of measles(खसरा) in the U.S. has triggered(activate,सक्रिय) a world-wide furore(zeal,उत्तेजना) over vaccinations. So what’s all the fuss about?
Ten-year-old Nithya* has never been vaccinated. The theory her parents — U.S.-returned working professionals — operate on is that if one eats healthy and keeps fit one does not need vaccinations. “After all our grandparents were never vaccinated and they lived long healthy lives,” they say. Another set of parents brings up the now-discredited link between the Measles-Mumps-Rubella (MMR) vaccine and autism as a reason for not vaccinating their children.

Following the large-scale outbreak of measles in the U.S. — triggered in Disneyland by the contact of unvaccinated children with a traveller infected with measles — between December 28, 2014 and March 13, 2015, California is trying to bring in a law that will require parents to vaccinate their children as a condition to enrol them in private or public schools. In one district of Washington State, 143 children were removed from school for not being vaccinated. In Australia, the government has removed all religious exemptions for vaccinations. With the U.S. now trying to tighten immunisation laws and the resultant uproar from the anti-vaccine lobby, this is a good time to look at what the furore is all about.

India accounts for more than one-third of all measles deaths among children in the world. According to the WHO, more than 300 outbreaks of measles, with 10,059 cases, were reported from 28 states of India in 2014. Measles being highly infectious, at least 95 per cent of all children need to receive two doses of the vaccine. Since around 15 per cent of vaccinated children fail to develop immunity from the first dose, an outbreak may be triggered if only 80 per cent are fully immunised. Boosted by a 63 per cent decline in the measles incidence rate — from 69.9 per million to 25 per million population — in 11 countries of the WHO’s southeast Asia Region, including India, coupled with a 48 per cent decline in measles deaths  between 2000 and 2011, the countries have committed to measles elimination from the region by 2020. In the case of the measles vaccine, at least 95 per cent of all children need to receive two doses. Elimination does not imply that there is no virus within the defined geographical region (this is eradication) but that there is no sustained transmission of endemic virus defined as an outbreak of more than 100 cases.

The goal of measles elimination, though tough, now seems attainable, given the success of the polio eradication campaign. India was one of the four polio-endemic ‘PAIN’ countries (Pakistan, Afghanistan, India, Nigeria) until January 13, 2011, when Rukhsar Khatoon from West Bengal was reported as the last child to be paralysed by polio in India. The cessation of transmission in India boosted the efforts towards global polio eradication. None of the three strains of wild poliovirus can survive for long periods outside the human body. Type 2 wild polio virus was eradicated in 1999. In April 2013, 458 experts from 80 countries, including 29 from India, signed a Scientific Declaration on Polio Eradication stating that unprecedented progress, scientific advances and new tools gave confidence that eradication is achievable. Countries in three WHO Regions (Americas, 1994; Western Pacific, 2000; Europe, 2002) have already been certified polio-free. After three years of maintaining the polio-free status, the Southeast Asia Region of World Health Organisation, comprising of 11 countries, was certified polio-free in March 2014, further raising the hopes for a world without polio.

Elimination of wild polio virus in India was achieved with high coverage of oral polio vaccine (OPV) coupled with an extensive awareness campaign to motivate people to have their children vaccinated. The gargantuan efforts amounted to 640,000 vaccination booths, 2.3 million vaccinators, 200 million doses of vaccine, 6.3 million ice packs, 191 million homes visited and 172 million children below five years of age immunised during the series of national immunisation days (Pulse Polio Day) across the country. However, India’s currently excellent OPV coverage is no guarantee against the importation of the highly contagious(infections,संक्रामक) wild polio virus from the remaining endemic countries and a resurgence of poliomyelitis. In fact, Pakistan, Afghanistan and Nigeria — the three endemic countries — face a range of challenges such as insecurity, weak health systems and poor sanitation. Polio can spread from these countries to infect children in other countries with inadequate vaccination. In late 2013, WHO reported the re-emergence of wild polio virus in Eastern Mediterranean countries with outbreaks in Syria and environmental circulation in Israel, Egypt and Palestine. This was attributed to low immunisation coverage in war-ravaged parts of Syria, collapsing health system and large population displacement creating pockets of highly susceptible unvaccinated children. Since 2012 Angola, Chad, the Democratic Republic of Congo and Sudan have reported polio outbreaks while another eight countries in Africa, along with Nepal, Kazakhstan, Tajikistan, Turkmenistan and Russia have had recent infections. Hence, high levels of polio vaccination coverage need to be continued to maintain adequately high immune levels among the population to prevent re-emergence or spread of imported wild polio virus.

Vaccines are a safe and effective way to protect children against specific diseases. Increases in vaccine coverage have, therefore, been seen as a paramount strategy for reducing infant and child death rates around the world. In fact, with the Bill & Melinda Gates Foundation pledging $10 billion over the next decade to help discover and develop vaccines and making them accessible to the world’s poorest countries, the period from 2010-2019 has been termed the “Decade of Vaccines”. In addition to the health benefits, expanding vaccine access may also facilitate major economic benefits to communities and governments. Scaling up the delivery of five life-saving vaccines and introducing a malaria vaccine could avert(avoid,दूर रहना) an estimated 6.4 million deaths among children below five years between 2011 and 2020 in 72 of the world’s poorest countries, according to the Lives Saved Tool developed by the Johns Hopkins Bloomberg School of Public Health, the WHO, and the Futures Institute. Nearly 1.5 million (23 per cent) of these would be from India, including averting 73 per cent of deaths due to measles (2,62,208), 48 per cent of pertussis (2,11,732), 25 per cent of meningitis (93,849), 24 per cent of pneumonia (6,37,925) and 15 per cent of diarrhoeal deaths (2,34,665). As a means to achieve the fourth Millennium Development Goal target of reducing by two-thirds the under-five child mortality rate between 1990 and 2015, the expansion of vaccination coverage is likely to be highly cost effective. Studies have even linked increases in vaccination coverage to improvements in human capital.

Routine childhood vaccines have been shown to have an impact above and beyond the expected prevention from the specific disease. Introduction of the measles vaccine led to greater reduction in overall child mortality than would be expected from reductions in measles mortality alone in certain communities of Bangladesh and Africa. Globally the annual number of child deaths fell from 12 million in 1990 to 7.6 million in 2010. Correspondingly, the measles vaccination coverage rate rose from 73 per cent to 84 per cent, according to WHO-UNICEF estimates. There is also evidence about the protective effect of the BCG vaccine against neonatal morality and increased mortality related to DPT vaccination in some settings. However, there are concerns about whether such findings — from both observational studies and randomised control trials — can be generalised to populations of different countries with varying levels of economic development, disease prevalence, and health care systems. Recently, McGovern and Canning from Harvard School of Public Health used data from 149 Demographic and Health Surveys in developing countries to estimate the association between all-cause mortality among children and the measles, BCG, DPT and Polio vaccination coverage. Increase in combined vaccination coverage was associated with 27 per cent reduction in mortality. Separately, the highest reduction in childhood mortality (17 per cent) was associated with measles vaccination.

Despite clear benefits and safety of vaccination, there are reports of parents choosing not to vaccinate their children, most often citing(mention,उल्लेख) the fear of the unknown, or worse, the anti-vaccination propaganda by certain sections of the media and even misinformed clinicians.  The most publicised of this anti-vaccine propaganda was The Lancet’s publication of reports in 1998 suggesting a relationship between the MMR vaccine and autistic spectrum disorders (ASD). This resulted in extensive and continuing attention from the public, the media, and health officials in the U.S. and the U.K. In 2001, an independent Immunisation Safety Review Committee of the Institute of Medicine, the U.S., rejected this view on the basis of evidence from published and unpublished studies. Though the committee concluded that the MMR vaccine could be administered safely, the damage had been done. Later a series of papers published in British Medical Journal in 2011 exposed how the lead author of the original study had fabricated the link between MMR vaccine and autism for financial gain. After 12 years of mounting evidence of criminal and ethical fraud, The Lancet retracted the article entirely.

Another challenge can be seen in the polio eradication: that of circulating Vaccine Derived Polio Viruses (cVDPVs) and Vaccine Associated Paralytic Polio (VAPP). The weakened virus in oral vaccine multiplies for some time in the intestine of vaccinated children but excreted VDPVs can spread in the immediate community, especially in areas with inadequate(not enough,अपर्याप्त) sanitation. In areas with very poor vaccination coverage the excreted VDPVs can continue to circulate for long periods, which if exceeds 12 months, provides a rare opportunity for the virus to mutate(change,परिवर्तित) and cause VAPP. Transmission of mutated VDPVs to unvaccinated children can lead to polio outbreaks. The problem is not with the vaccine itself, but low vaccination coverage.

Globally, nearly three billion children have been administered more than 10 billion doses of OPV in the last 15 years. During this period, only 20 cVDPV outbreaks reportedly occurred in 20 countries, resulting in 758 VDPV cases worldwide. In India, 42 cVDPV cases have been detected since 2009 — 21 in 2009, five in 2010, seven in 2011, one in 2012, five in 2013 and three in 2014. The key to protection against both vaccine-derived and wild polioviruses is full immunisation.

The WHO recommends that all countries using OPV must monitor VAPP. Globally, India has the highest incidence of VAPP — one case for 143,000 birth cohorts(group,दल) in comparison with one per 750,000 in the U.S. As per the WHO’s strategy for ‘Polio Eradication and Endgame Strategic Plan’ towards a polio-free world by 2018, at least one dose of IPV is to be introduced into routine immunisation programmes globally, after which trivalent oral polio vaccines should be replaced with bivalent OPV (remove vaccine virus type 2 that is responsible for 95 per cent of cVDPV cases in the last three years) until global eradication of polio virus is achieved. There is a concern that when OPV is withdrawn, there will be a period when vaccine viruses shed by the OPV-vaccinated children may be transmitted to immunity-naive infants and children, creating a potential for large scale emergence of VDPV associated outbreaks if conditions become suitable. The elimination of VDPVs using IPV has been called phase two of polio eradication. For countries such as India, that use OPV to eradicate wild polio virus, the need for a second phase is essential for the eradication of vaccine polioviruses. The academia and researchers in India are still divided over the timing of incorporation of IPV in the routine immunisation schedule.

A number of concerns have been raised about the safety of, and need for, certain immunisations. There is an evolving surveillance system for adverse events following immunisation in India for the vaccines delivered through government sector. Participation of private doctors — negligible at present — will provide vital information on the safety of new and underutilised vaccines that are not part of the government programme. IAP provides a platform to all paediatricians to report all vaccination-associated adverse events to the IAP immunisation website (www.iapcoi.com). In collaboration with Vodafone, the IAP has launched ImmunizeIndia to send notifications through text messages on mobile phones to remind parents about their children’s immunization schedule (www.immunizeindia.org). In December 2014, the Government of India launched Mission Indradhanush to vaccinate more than 89 lakh unvaccinated children in the country to achieve 90 per cent full immunisation coverage (65 per cent at present), against seven life-threatening diseases (diphtheria, whooping cough, tetanus, polio, tuberculosis, measles and hepatitis B) in the next five years.

The recent controversies and allegations related to immunisation safety show an erosion of public trust in those responsible for vaccine research, development, licensure, schedules, and policy-making. The triad of scientific evidence, economic principles, and public health ethics should form the foundation for all policy making. Right from research and development followed by marketing of childhood vaccines and the ultimate decision of the parents to use them is a matter of balancing the choices between the government’s and industry’s interests, the clinicians’ and public health professionals’ perspective and individual and population benefit. The eventual choice should not infringe upon an individual’s right to enjoy the highest attainable standard of health as a basic human right.   

Quick Facts

Currently the Government of India provides free childhood vaccination for seven diseases — tuberculosis, diphtheria, pertussis/whooping cough, tetanus, poliomyelitis, measles and Hepatitis B —under its Universal Immunization Programme (UIP).

A conjugate Pentavac vaccine (Diphtheria, Tetanus, Pertussis, Hepatitis B & Haemophilus Type b) was included as a pilot project in selected states in 2011.

Four new vaccines for polio (injectable), rotavirus, rubella, and Japanese encephalitis (179 districts) will soon be included according to the recommendation of National Technical Advisory Group of India.

Other vaccines recommended by the Indian Academy of Paediatrics (IAP) are typhoid, Hepatitis A, and chicken pox for routine use and influenza, meningitis, Japanese Encephalitis, Cholera, Rabies, Yellow Fever and Pneumococcal vaccines under special circumstances for children at high risk.